Here's a thought. 8-9 years ago when I last got into cycling I was well overweight (as I am now) and unfit (as I am now) and every Saturday I would work my way up to a 100km cycle.
I had finally worked out a route that would bring me back home at just over 100kms, but while I felt great during the first stretch, every week on the exact same stretch (around 50-60kms) I would lose all energy very quickly and stop at the same train station every week, sit there and rest and take the train back home hardly being able to keep my eyes open on the train.
This went on for a long time until I asked for advice, someone said to drink more water and lo-and-behold, I made it all the way back, jumping from +/-60kms to 100kms in one week. That was the last train station on that route so thereafter the only choice was all the way home, but more importantly I didn't have that very quick dip in energy that made me want to fall asleep on the train every previous week.

A few months later I had a kidney stone stuck somewhere that caused all kinds of health issues that wasted 9 months of my life. I didn't put the two things together back then, but I do wonder now whether regular dehydration from cycling was the cause for the kidney stone. Needless to say, when I get my new bike this weekend (hopefully), I'm fitting 2 bottle cages and making a point to develop the habit of drinking regularly!!

Any thought? Seems plausible to me.

Being dehydrated could probably contribute towards kidney stones but there would have been other factors too such as your diet and not drinking enough water in general.

You will find how much water you need here how-many-bottles-for-taupo-t109495.html

What are you eating and drinking on your rides, and how much?
For a 100km ride I'd be looking at 1/8th a Peakfuel cookie and a mouthful of Peakfuel fluids every 15 minutes, but thats what I'm used to - whatever you use, you might need more than water at that distance.

fatass wrote:Here's a thought. 8-9 years ago when I last got into cycling I was well overweight (as I am now) and unfit (as I am now) and every Saturday I would work my way up to a 100km cycle.
I had finally worked out a route that would bring me back home at just over 100kms, but while I felt great during the first stretch, every week on the exact same stretch (around 50-60kms) I would lose all energy very quickly and stop at the same train station every week, sit there and rest and take the train back home hardly being able to keep my eyes open on the train.
This went on for a long time until I asked for advice, someone said to drink more water and lo-and-behold, I made it all the way back, jumping from +/-60kms to 100kms in one week. That was the last train station on that route so thereafter the only choice was all the way home, but more importantly I didn't have that very quick dip in energy that made me want to fall asleep on the train every previous week.

A few months later I had a kidney stone stuck somewhere that caused all kinds of health issues that wasted 9 months of my life. I didn't put the two things together back then, but I do wonder now whether regular dehydration from cycling was the cause for the kidney stone. Needless to say, when I get my new bike this weekend (hopefully), I'm fitting 2 bottle cages and making a point to develop the habit of drinking regularly!!

Any thought? Seems plausible to me.

I think this is quite likely to be correct. I had never had Kidney stones until I started working in a job where it was difficult to get to the loo. So I deliberately cut back my fluid intake a lot during the day. Got a Kidney stone after a month and a bit, faaaark they hurt.